The present invention relates generally to medical treatments. More specifically, the present invention relates to dialysis therapies and dialyzers.
Due to diseases, insult or other causes, the renal system can fail. In renal failure of any cause, there are several physiological derangements. The balance of water, minerals (Na, K, Cl, Ca, P, Mg, SO4) and the excretion of daily metabolic load of fixed hydrogen ions is no longer possible in renal failure. During renal failure, toxic end products of nitrogen metabolism (urea, creatinine, uric acid, and others) can accumulate in blood and tissues.
Dialysis processes have been devised for the separation of elements in a solution by diffusion across a semi-permeable membrane (diffusive solute transport) down a concentration gradient. Principally, dialysis comprises two methods: hemodialysis; and peritoneal dialysis.
Hemodialysis treatment utilizes the patient""s blood to remove waste, toxins, and excess water from the patient. The patient is connected to a hemodialysis machine and the patient""s blood is pumped through the machine. Catheters are inserted into the patient""s veins and arteries to connect the blood flow to and from the hemodialysis machine. Waste, toxins, and excess water are removed from the patient""s blood and the blood is infused back into the patient. Hemodialysis treatments last several hours and are generally performed in a treatment center about three to four times per week.
Hemodialysis typically involves the use of a dialyzer. Dialyzers generally comprise a housing or casing. Located within the interior of the casing is a fiber bundle. Typically the fiber bundle is comprised of a number of membranes that are oriented parallel to each other. The membranes are designed to allow blood to flow therethrough with dialysate flowing on the outside of the membranes. Due to an osmotic gradient that is created, waste products are removed from the blood through the membranes into the dialysate.
Accordingly, dialyzers typically include a blood inlet and a blood outlet. The blood inlet is designed to cause blood to enter the fiber membranes and flow therethrough through the blood outlet. Dialysate is designed to flow through an inlet of the dialyzer and out of the dialyzer through an outlet. The dialysate is designed to flow across the outside or exterior walls of the membranes.
One of the issues with prior dialyzers is that the flow of dialysate around the fiber bundles may not be entirely satisfactory. In this regard, dialysate may not flow sufficiently around the entire fiber bundle. Rather shunts between the bundle and the case may occur. This can result in a reduced flow of dialysate around certain portions of membranes contained in the center of the fiber bundle. The clearance of the dialyzer will therefore be reduced.
Accordingly, efforts have been directed at designing dialyzers wherein there is a better perfusion of dialysate into the fiber bundle and specifically the center thereof.
The present invention provides improved dialyzers and methods for providing dialysis. In this regard, the present invention provides a dialyzer having an improved perfusion of dialysate into the fiber bundle.
To this end, in an embodiment of the present invention, a dialyzer is provided comprising a casing defining an interior and including a dialysate inlet and a dialysate outlet. A plurality of fibers are located in the interior of the casing and define a fiber bundle. A dialysate inlet fluid channel is provided in fluid communication with the dialysate inlet and includes a plurality of flutes that extend into a portion of the fiber bundles, the flutes define an opening for allowing dialysate to flow from the inlet fluid channel into the interior of the casing.
In an embodiment, the dialyzer includes a dialysate outlet fluid channel in fluid communication with the dialysate outlet that includes a plurality of flutes that extend into a portion of the fiber bundle. The flutes define openings for allowing dialysate to flow from the interior of the casing into the dialysate outlet fluid channel.
In an embodiment, the outlet fluid channel and inlet fluid channel have substantially the same structure.
In an embodiment, the casing is constructed from plastic.
In an embodiment, the dialyzer includes eight flutes.
In an embodiment, a top portion of the dialysate inlet is defined by potting material.
In an embodiment, the flutes circumscribe an entire circumference of a first end of the dialyzer.
In an embodiment, the opening in the flutes is a slot.
In an embodiment, each flute defines a separate opening.
In another embodiment of the present invention, a dialyzer is provided comprising a casing defining an interior and having a first end having a dialysate inlet and a second end having a dialysate outlet. A fiber bundle including a plurality of fibers is located within the interior and extends from the first end to the second end. A fluid inlet channel in fluid communication with the dialysate inlet is provided, the fluid inlet channel being defined, in part, by a portion of the casing that defines an exterior surface of the first end and an inner wall that circumscribes a portion of the interior. The inner wall includes portions that extend into the fiber bundle. At least one of the portions includes an aperture for allowing fluid to flow from the channel into the interior. A fluid outlet channel in fluid communication with the dialysate outlet is provided. The fluid outlet channel is defined, in part, by a portion of the casing that defines an exterior surface of the first end and an inner wall that circumscribes a portion of the interior. The inner wall includes portions that extend into the fiber bundle, at least one of the portions including an aperture for allowing fluid to flow from the channel into the interior.
In an embodiment, the inner wall defines a pluality of semicircular structures.
In an embodiment, the fluid inlet channel and fluid outlet channel includes at least six separate portions that extend into the fiber bundle each including an aperture.
In yet another embodiment of the present invention, a dialyzer is provided comprising a casing defining an interior having a fiber bundle located therein and including a first end having a dialysate inlet and a second end having a dialysate outlet. The casing including a dialysate inlet in fluid communication with an inlet fluid channel, the inlet fluid channel defined, at least in part, by an interior wall of the casing, a potting material and an inner wall circumscribing the interior of the first end. The inner wall includes a plurality of members defining areas for receiving fibers of the fiber bundle and a portion that extends into the fiber bundles. Each of the portions of the inner wall that extend into the fiber bundles and include an aperture for allowing dialysate to flow into the interior of the casing.
In an embodiment, the portions define flutes.
In a further embodiment of the present invention, a method for providing dialysis to a patient is provided. The method comprising the steps of passing blood through fiber bundles of a dialyzer and passing dialysate through the dialyzer such that the dialyzer includes portions that separate a portion of the fiber bundle causing more dialysate to flow to an interior of the fiber bundle.
An advantage of the present invention is to provide an improved dialyzer.
A further advantage of the present invention is to provide an improved method of providing dialysis to a patient.
Still further, an advantage of the present invention is to provide an improved housing design for a dialyzer.
Furthermore, an advantage of the present invention is to provide improved fluid flow characteristics in a dialyzer.
Additionally, an advantage of the present invention is to provide a dialyzer having improved efficiency.
Another advantage of the present invention is to provide an improved dialyzer for hemodialysis.
Moreover, an advantage of the present invention is to provide an improved dialyzer that can be used in a number of therapies.
Additional features and advantages of the present invention will be described in and apparent from the detailed description of the presently preferred embodiments and the figures.